CS50 PSET2 code will not compile

Question

I would appreciate any help that could be given with my code below (+ error codes below that):

My code will not compile and the primary error apparently is an "undeclared identifier" refering to argv. however i believe i have identified the string array in the initial line (int main argc string argv[MaxprobaleInput])

Any other flaws in my code that anyone can see would also be greatly appreciated.

#include <cs50.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>

//DECLARE VARIABLES TO BE USED IN CODE GLOBALLY

int MaxProbableInput = 12;
int MinimumProgInput = 2;
int IterateUserInput = 0;
int UserInputCharCount = strlen(argv);

int main(int argc, string argv [MaxProbableInput])
{
    //MAKE SURE THE USER INPUTS A NAME AT COMMAND LINE

    if (argc <= MinimumProgInput)

    {
        printf("The proramme requires your full name to execute. e.g: ./initials Chengetai Chiwanga\n");

    return 1;
}
    //PRINT THE FIRST LETTER OF THE USER INPUT IN CAPS

    if  (argv[0] != ' ' && argv[0] != NULL)

    {

        printf("%c,toupper argv [0][1]);

    }

    //PRINT CONCURRENT INITIALS OF THE USERS INPUT IN CAPS

        for (IterateUserInput; IterateUserInput < UserInputCharCount; IterateUserInput++)

        if (UserInputCharCount == ' ' && UserInputCharCount [IterateUserInput + 1] != NULL)
        {

        printf("%c", topupper argv[IterateUserInput + 1] );

        return 0;

        }

    }

}

Error codes:

clang -fsanitize=signed-integer-overflow -fsanitize=undefined -ggdb3 -O0 -std=c11 -Wall -Werror -Wextra -Wno-sign-compare -Wshadow    initials.c  -lcrypt -lcs50 -lm -o initials

initials.c:11:33: error: use of undeclared identifier 'argv'
int UserInputCharCount = strlen(argv);
                            ^
initials.c:26:22: error: comparison between pointer and integer ('string' 
(aka 'char *') and 'int') [-Werror]
    if  (argv[0] != ' ' && argv[0] != NULL)
         ~~~~~~~ ^  ~~~
initials.c:30:33: error: expected ')'
        printf("%c",toupper argv [0][1]);
                            ^
initials.c:30:19: note: to match this '('
        printf("%c",toupper argv [0][1]);
              ^
initials.c:38:69: error: subscripted value is not an array, pointer, or vector
            if (UserInputCharCount == ' ' && UserInputCharCount [IterateUserInput + 1] != NULL)
                                             ~~~~~~~~~~~~~~~~~~ ^~~~~~~~~~~~~~~~~~~~~
initials.c:41:38: error: expected ')'
            printf("%c", toupper argv[IterateUserInput + 1] );
                                 ^
initials.c:41:23: note: to match this '('
            printf("%c", toupper argv[IterateUserInput + 1] );
                  ^
initials.c:36:22: error: expression result unused [-Werror,-Wunused-value]
            for (IterateUserInput; IterateUserInput < UserInputCharCount; IterateUserInput++)
                 ^~~~~~~~~~~~~~~~
6 errors generated.
make: *** [initials] Error 1

Thanks in advance.

PotNoodle

Answer 1

First, argv is a parameter of main, so you cannot access it in a global context. I don't see the point in those global variables either. Better have as few global variables as possible.

Second, function signature of main should be int main(int argc, char *argv[]) (string is an alias for char*, so string argv[] is the same as char*argv[] or even char**argv). No array length.

Third, as argv is a list of strings, with the number of strings stored in argc. First element (at index 0) is usually the programme name, the others are the arguments passed on command line.